Preparation of n-phenylbenzoquinone-imine and converting same into p-phenylenediamines

Abstract

N-phenylbenzoquinone-imine is prepared by oxidizing N-(4-hydroxyphenyl)aniline in a liquid, at least partially organic reaction medium, in the presence of a basic compound and, advantageously, a catalytically effective amount of at least one manganese, copper, cobalt and/or nickel compound; this imine can be reacted with an aliphatic or cycloaliphatic amine to produce an N-phenyl-N'-cycloalkyl-para-phenylene-diamine and an N-phenyl-N'-cycloalkyl-2,5-cyclohexadiene-1,4-diimine, such 1,4-diimine itself being easily reduced to the corresponding p-phenylenediamine.

We claim: 
     
       1. A process for the preparation of N-phenylbenzoquinone-imine, comprising oxidizing N-(4-hydroxyphenyl)aniline in an at least partially organic liquid reaction medium, in the presence of a basic tertiary amine compound. 
     
     
       2. The process as defined by claim 1, carried out in the presence of a catalytically effective amount of a manganese, copper, cobalt and/or nickel compound. 
     
     
       3. The process as defined by claim 1, said liquid reaction medium being wholly organic. 
     
     
       4. The process as defined by claim 1, said tertiary amine having the formula (I): ##STR5## wherein R 1  and R 2 , which may be identical or different, are each a linear or branched chain alkyl radical having 1 to 12 carbon atoms or a phenyl radical, and R 3  is a linear or branched chain alkyl radical having 1 to 12 carbon atoms, a linear or branched chain alkenyl radical having 2 to 12 carbon atoms, a phenyl radical, a substituted phenyl radical bearing one or two linear or branched chain alkyl radicals having 1 to 4 carbon atoms, a cyclohexyl or cyclopentyl radical, or a benzyl or phenethyl radical. 
     
     
       5. The process as defined by claim 4, wherein the amount of said tertiary amine is at least 1 molar % of the molar amount of said N-(4-hydroxyphenyl)aniline. 
     
     
       6. The process as defined by claim 5, said amount of tertiary amine ranging from 1% to 1,000%. 
     
     
       7. The process as defined by claim 6, said amount of tertiary amine ranging from 50% to 300%. 
     
     
       8. The process as defined by claim 4, wherein the tertiary amine of formula (I) is a non-quaternizable tri-alkylamine in which R 1 , R 2  and R 3  are linear or branched chain alkyl radicals having from 1 to 12 carbon atoms. 
     
     
       9. The process as defined by claim 1, said wholly organic liquid reaction medium comprising an inert solvent. 
     
     
       10. The process as defined by claim 9, said inert solvent comprising an alcohol, ether, ketone, nitrile, N-alkylatedamide, aliphatic or chlorinated aliphatic hydrocarbon, aromatic or chlorinated aromatic hydrocarbon, cycloaliphatic hydrocarbon, ester or sulfoxide. 
     
     
       11. The process as defined by claim 1, said liquid reaction medium comprising a hydro/organic biphasic reaction medium. 
     
     
       12. The process as defined by claim 11, said basic compound comprising an alkali metal hydroxide. 
     
     
       13. The process as defined by claim 12, wherein the molar ratio alkali metal hydroxide/N-(4-hydroxyphenyl)aniline ranges from 5% to 500%. 
     
     
       14. The process as defined by claim 13, said ratio ranging from 10% to 100%. 
     
     
       15. The process as defined by claim 11, said biphasic reaction medium comprising an aliphatic hydrocarbon, chlorinated aliphatic hydrocarbon, aromatic hydrocarbon, chlorinated aromatic hydrocarbon or cycloaliphatic hydrocarbon. 
     
     
       16. The process as defined by claim 12, wherein the water/organic solvent ratio by volume ranges from 0.01 to 100. 
     
     
       17. The process as defined by claim 16, said ratio ranging from 0.1 to 10. 
     
     
       18. The process as defined by claim 2, such metal compound comprising a salt of a mono- or polyfunctional carboxylic acid, or of a halocarboxylic acid, or of a mineral acid, or an oxide or hydroxide.